Sunan at-Tirmidhi (Jami-al-Tirmidhi), Chapter: Salah (Prayers)

Once the Prophet (SAW) was seated in the mosquc and we were with him. A villager came and offered a brief salah and on finishing it he offered salaam to the Prophet (SAW). He said, "Go and offer salah. You have not offered it." He went back and repeated it and came back and greeted the Prophet (SAW) but he said, "Go and offer salah for you have not observed it." This happened twice or thrice. Each time, he came offered salaam and the-Prophet (SAW) told him to go and offer salah, for he had not done it. The people were worried because of that, imagining that whoever offered a brief prayer had not actually prayed. So, this man said finally. "Teach me, for I am a human who may be right as well as mistaken." The Prophet (SAW) said, "Okay! When you come for prayer, make ablution as Allah has commanded. Then call the adhan and the iqamah. Then if you remember something from the Qur'an, recite it otherwise praise Allah and extol him and recite "There is no God but Allah". Then go into ruku and bow down in a composed manner. Then stand up straight. Then go into sajdah in a careful way and then sit peacefully. Then stand up. If you do that then your salah is perfect but if there is a lapse then there will be a lapse in your salah."